(a) Technical Field of the Invention
The present invention is related to a new construction of an open end adjustable spanner, and more particularly to one which allows easy alignment with the bolt or nut and avoids slipping therefrom before and after tightening or loosening up the bolt or nut.
(b) Description of the Prior Art
An open-end adjustable spanner is one of the common hand tools either at home or in a factory. According to the survey, the ordinary open-end spanner is the most popular hand tool. However, it is the least handy and economic tool since its working angle is limited within 15 degrees of travel. Another type of single acting adjustable spanner though operating on single latch and ratchet to execute a local transmission by the circumference of the serrated section of the ratchet, normal transmission of force is prevented at the gap of the circumference of the ratchet. Accordingly, the single acting adjustable spanner is unsatisfactory in use. Another type yet of an adjustable spanner has on both sides of the gap of the ratchet respectively adapted with a latch to constitute a leverage engagement so that the force applied to either or both of the latches execute the transmission of gearing progression to continuously transmit multiplied force. Consequently, the adjustable spanner with two latches is fast, handy and effort-saving in operation. However, the width of the opening of the adjustable spanner with two latches is usually fixed. Therefore, in clamping bolt or nut in various sizes, frequent exchange of spanner is required and becomes annoying. Furthermore, since the orientation of the opening is fixed, it makes the clamping awkward, that is, difficult to align at the work piece, particularly so true when operating within a very limited space.